It could be a crack in the fuel bulb/line......

But my bet is a clogged jet in the Carb. What I do.....is squirt [using a spray can] some carb cleaner through each hole in the carb until I see the cleaner coming out somewhere. Some of the holes maybe hard to get to, but usually can be done. Also you can try sticking a small wire into each hole and see if it will come out the other side.

Be careful not to get your face sprayed..... wear goggles.

If you are soaking the carb..... put it in a plastic jar and shake it up seveal times and let is sit over night.

Not sure what you mean..... when you push in the little bulb, it only pumps air???????? If so.... you got an crack somewhere in a fuel line or the primer bulb. With that old of an engine..... fuel lines are probably brittle and need replacing. Cheapest place to buy the tubing is Western Auto store...... just north of the Walgreens on Hwy 171.

If the new fuel line are hard to slide on the "connector"....heat the end of the rubber with a hair drier to soften it up some, and then it will slide on.

ya got dirt in the idle jets it wont idle when the butterfly is closed there are two to three little hole that let fuel pass so it will idle sounds like there clogged up..find them holes they will be on the top part of the venturi on the engine side of the carb.